Intelligence shows a massive increase in Asian betting on Australian sporting events, with up to $40 million held off-shore on one A-League game. Asian syndicates, both legal and illegal, are estimated to turn over about $2 billion a month.

The Victorian deputy police commissioner, Graham Ashton, said match fixing ''is imminent'' in Australia. ''It is a growing area of concern for us. This thing is coming down the highway and we have to be prepared."

Earlier this week European police said up to 700 soccer games were suspected of being fixed by a syndicate based in Singapore.

The Football Federation Australia chief executive, David Gallop, said the sport was committed to deterring any form of corruption and had recently commenced an 18-month agreement with Sportradar, an independent betting monitoring organisation.

The AFL is briefing all players on the dangers of associating with criminals and the risks of being groomed by illegal betting cartels. The AFL chief, Andrew Demetriou, said the risk of sports corruption ''is a massive concern to us'' and the commission's integrity unit, set up in 2008, would be expanded this year.

''We are quite well placed but we know we have more to do.''

He said the league would employ more investigators and invest in technology to check suspect players' deleted texts and tweets - a method used in US baseball.

Police cannot warn codes of the activities of at-risk players as the information is usually gathered via confidential phone taps.

It is understood some AFL players have been picked up on phone taps purchasing narcotics and talking of drug use. They have not been targeted as the police investigations have centred on high-end traffickers rather than users. Victorian police say the tapes could be used in any subsequent match-fixing investigations.

Police are also concerned that international players imported to play in local tournaments may have pre-existing relationships with illegal bookmakers.

The NSW Sports Minister, Graham Annesley, has previously told Fairfax Media there was ''no bigger threat to the integrity of sport'' than match fixing, as the government last year became the first state to enact tough new laws that punish corruption in sport by sentences of up to 10 years in jail. The legislation was proposed after a NSW Law Reform Commission report on match fixing found sports betting had become a huge industry in Australia.

Rugby league has already been hit by a match-fixing scandal. In 2010 the NSW Police's Casino and Racing Investigations unit investigated a huge betting plunge on a game between the Canterbury Bulldogs and North Queensland Cowboys. The investigation led to six people being charged, with one player, Ryan Tandy, convicted and fined over the incident.

NSW Police declined to comment on the latest revelations from Victoria.